Field of the Invention
This invention relates to a capacitive touch panel, especially to a capacitive touch panel having a single-layer touch sensor.
Description of the Related Art
In general, the conventional capacitive touch panel uses multiple-layer sensing structure to sense touch points. However, it has disadvantages of complicated structure and higher cost. Therefore, the capacitive touch panel having a single-layer touch sensor is provided to use a single conductive layer to replace the conventional X-axis electrode layer and Y-axis electrode layer.
Please refer to FIG. 1A, FIG. 1B, and FIG. 2. FIG. 1A and FIG. 2 illustrate top-views of two different single-layer sensing structures of the conventional capacitive touch panel; FIG. 1B illustrates a cross-sectional diagram of the single-layer sensing structure along AA′ in FIG. 1.
As shown in FIG. 1A, X-axis electrodes X1˜X2 and Y-axis electrodes Y1˜Y2 are disposed at the same plane through bridge structures BX and BY. However, once the bridge structures are used, the entire manufacturing processes and the material choice will become more complicated and the cost is hard to be reduced. For example, the bridge structure shown in FIG. 1A is usually made by three mask processes, the bridge structure BX of X-axis electrode and the bridge structure BY of Y-axis electrode can both use transparent material the same with the electrodes, such as ITO, IZO, nano-Ag, or nano-carbon tube, and an isolation layer ISO is disposed between the bridge structure BX of X-axis electrode and the bridge structure BY of Y-axis electrode as shown in FIG. 1B to prevent the short circuit. In fact, the material of the isolation layer ISO can be organic material or inorganic material.
As shown in FIG. 2, the X-axis electrodes X1˜X3 and the Y-axis electrodes Y1˜Y3 can be also disposed on the same plane through a symmetric arrangement that one Y-axis electrode corresponds one X-axis electrode; however, the traces LX1˜LX3 of the X-axis electrodes X1˜X3 and the traces LY1˜LY3 of the Y-axis electrodes Y1˜Y3 must be disposed within the active area of the conventional capacitive touch panel, this will make some active area of the conventional capacitive touch panel become inactive, and the touch sensing performance of the conventional capacitive touch panel will become poor.
Therefore, the invention provides a capacitive touch panel having a single-layer touch sensor to solve the above-mentioned problems.